1
|
Camblor-Perujo S, Ozer Yildiz E, Küpper H, Overhoff M, Rastogi S, Bazzi H, Kononenko NL. The AP-2 complex interacts with γ-TuRC and regulates the proliferative capacity of neural progenitors. Life Sci Alliance 2024; 7:e202302029. [PMID: 38086550 PMCID: PMC10716017 DOI: 10.26508/lsa.202302029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
Centrosomes are organelles that nucleate microtubules via the activity of gamma-tubulin ring complexes (γ-TuRC). In the developing brain, centrosome integrity is central to the progression of the neural progenitor cell cycle, and its loss leads to microcephaly. We show that NPCs maintain centrosome integrity via the endocytic adaptor protein complex-2 (AP-2). NPCs lacking AP-2 exhibit defects in centrosome formation and mitotic progression, accompanied by DNA damage and accumulation of p53. This function of AP-2 in regulating the proliferative capacity of NPCs is independent of its role in clathrin-mediated endocytosis and is coupled to its association with the GCP2, GCP3, and GCP4 components of γ-TuRC. We find that AP-2 maintains γ-TuRC organization and regulates centrosome function at the level of MT nucleation. Taken together, our data reveal a novel, noncanonical function of AP-2 in regulating the proliferative capacity of NPCs and open new avenues for the identification of novel therapeutic strategies for the treatment of neurodevelopmental and neurodegenerative disorders with AP-2 complex dysfunction.
Collapse
Affiliation(s)
| | - Ebru Ozer Yildiz
- CECAD Excellence Center, University of Cologne, Cologne, Germany
| | - Hanna Küpper
- CECAD Excellence Center, University of Cologne, Cologne, Germany
| | - Melina Overhoff
- CECAD Excellence Center, University of Cologne, Cologne, Germany
- Center for Physiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Saumya Rastogi
- CECAD Excellence Center, University of Cologne, Cologne, Germany
| | - Hisham Bazzi
- CECAD Excellence Center, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Department of Dermatology and Venereology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
| | - Natalia L Kononenko
- CECAD Excellence Center, University of Cologne, Cologne, Germany
- Center for Physiology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Center for Molecular Medicine Cologne, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany
- Institute of Genetics, Natural Faculty, University of Cologne, Cologne, Germany
| |
Collapse
|
2
|
Lucas L, Cooper TA. Insights into Cell-Specific Functions of Microtubules in Skeletal Muscle Development and Homeostasis. Int J Mol Sci 2023; 24:ijms24032903. [PMID: 36769228 PMCID: PMC9917663 DOI: 10.3390/ijms24032903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/17/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
The contractile cells of skeletal muscles, called myofibers, are elongated multinucleated syncytia formed and maintained by the fusion of proliferative myoblasts. Human myofibers can be hundreds of microns in diameter and millimeters in length. Myofibers are non-mitotic, obviating the need for microtubules in cell division. However, microtubules have been adapted to the unique needs of these cells and are critical for myofiber development and function. Microtubules in mature myofibers are highly dynamic, and studies in several experimental systems have demonstrated the requirements for microtubules in the unique features of muscle biology including myoblast fusion, peripheral localization of nuclei, assembly of the sarcomere, transport and signaling. Microtubule-binding proteins have also been adapted to the needs of the skeletal muscle including the expression of skeletal muscle-specific protein isoforms generated by alternative splicing. Here, we will outline the different roles microtubules play in skeletal muscle cells, describe how microtubule abnormalities can lead to muscle disease and discuss the broader implications for microtubule function.
Collapse
Affiliation(s)
- Lathan Lucas
- Chemical, Physical, Structural Biology Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Thomas A. Cooper
- Chemical, Physical, Structural Biology Graduate Program, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
- Department of Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
- Correspondence:
| |
Collapse
|
3
|
Camblor-Perujo S, Kononenko NL. Brain-specific functions of the endocytic machinery. FEBS J 2021; 289:2219-2246. [PMID: 33896112 DOI: 10.1111/febs.15897] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 03/29/2021] [Indexed: 12/12/2022]
Abstract
Endocytosis is an essential cellular process required for multiple physiological functions, including communication with the extracellular environment, nutrient uptake, and signaling by the cell surface receptors. In a broad sense, endocytosis is accomplished through either constitutive or ligand-induced invagination of the plasma membrane, which results in the formation of the plasma membrane-retrieved endocytic vesicles, which can either be sent for degradation to the lysosomes or recycled back to the PM. This additional function of endocytosis in membrane retrieval has been adopted by excitable cells, such as neurons, for membrane equilibrium maintenance at synapses. The last two decades were especially productive with respect to the identification of brain-specific functions of the endocytic machinery, which additionally include but not limited to regulation of neuronal differentiation and migration, maintenance of neuron morphology and synaptic plasticity, and prevention of neurotoxic aggregates spreading. In this review, we highlight the current knowledge of brain-specific functions of endocytic machinery with a specific focus on three brain cell types, neuronal progenitor cells, neurons, and glial cells.
Collapse
Affiliation(s)
| | - Natalia L Kononenko
- CECAD Cluster of Excellence, University of Cologne, Germany.,Center for Physiology & Pathophysiology, Medical Faculty, University of Cologne, Germany
| |
Collapse
|
4
|
Sharma G, Pfeffer G, Shutt TE. Genetic Neuropathy Due to Impairments in Mitochondrial Dynamics. BIOLOGY 2021; 10:268. [PMID: 33810506 PMCID: PMC8066130 DOI: 10.3390/biology10040268] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 03/19/2021] [Accepted: 03/21/2021] [Indexed: 12/12/2022]
Abstract
Mitochondria are dynamic organelles capable of fusing, dividing, and moving about the cell. These properties are especially important in neurons, which in addition to high energy demand, have unique morphological properties with long axons. Notably, mitochondrial dysfunction causes a variety of neurological disorders including peripheral neuropathy, which is linked to impaired mitochondrial dynamics. Nonetheless, exactly why peripheral neurons are especially sensitive to impaired mitochondrial dynamics remains somewhat enigmatic. Although the prevailing view is that longer peripheral nerves are more sensitive to the loss of mitochondrial motility, this explanation is insufficient. Here, we review pathogenic variants in proteins mediating mitochondrial fusion, fission and transport that cause peripheral neuropathy. In addition to highlighting other dynamic processes that are impacted in peripheral neuropathies, we focus on impaired mitochondrial quality control as a potential unifying theme for why mitochondrial dysfunction and impairments in mitochondrial dynamics in particular cause peripheral neuropathy.
Collapse
Affiliation(s)
- Govinda Sharma
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada;
| | - Gerald Pfeffer
- Departments of Clinical Neurosciences and Medical Genetics, Cumming School of Medicine, Hotchkiss Brain Institute, Alberta Child Health Research Institute, University of Calgary, Calgary, AB T2N 4N1, Canada;
| | - Timothy E. Shutt
- Departments of Medical Genetics and Biochemistry & Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute, Hotchkiss Brain Institute, University of Calgary, Calgary, AB T2N 4N1, Canada;
| |
Collapse
|
5
|
Patrick MT, Stuart PE, Zhang H, Zhao Q, Yin X, He K, Zhou XJ, Mehta NN, Voorhees JJ, Boehnke M, Gudjonsson JE, Nair RP, Handelman SK, Elder JT, Liu DJ, Tsoi LC. Causal Relationship and Shared Genetic Loci between Psoriasis and Type 2 Diabetes through Trans-Disease Meta-Analysis. J Invest Dermatol 2020; 141:1493-1502. [PMID: 33385400 DOI: 10.1016/j.jid.2020.11.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/09/2020] [Accepted: 11/23/2020] [Indexed: 01/04/2023]
Abstract
Psoriasis and type 2 diabetes (T2D) are complex conditions with significant impacts on health. Patients with psoriasis have a higher risk of T2D (∼1.5 OR) and vice versa, controlling for body mass index; yet, there has been a limited study comparing their genetic architecture. We hypothesized that there are shared genetic components between psoriasis and T2D. Trans-disease meta-analysis was applied to 8,016,731 well-imputed genetic markers from large-scale meta-analyses of psoriasis (11,024 cases and 16,336 controls) and T2D (74,124 cases and 824,006 controls), adjusted for body mass index. We confirmed our findings in a hospital-based study (42,112 patients) and tested for causal relationships with multivariable Mendelian randomization. Mendelian randomization identified a causal relationship between psoriasis and T2D (P = 1.6 × 10‒4, OR = 1.01) and highlighted the impact of body mass index. Trans-disease meta-analysis further revealed four genome-wide significant loci (P < 5 × 10‒8) with evidence of colocalization and shared directions of effect between psoriasis and T2D not present in body mass index. The proteins coded by genes in these loci (ACTR2, ERLIN1, TRMT112, and BECN1) are connected through NF-κB signaling. Our results provide insight into the immunological components that connect immune-mediated skin conditions and metabolic diseases, independent of confounding factors.
Collapse
Affiliation(s)
- Matthew T Patrick
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Philip E Stuart
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Haihan Zhang
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Biostatistics, Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Qingyuan Zhao
- Statistical Laboratory, Centre for Mathematical Sciences, University of Cambridge, Cambridge, United Kingdom
| | - Xianyong Yin
- Department of Biostatistics, Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Kevin He
- Department of Biostatistics, Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Xu-Jie Zhou
- Renal Division, Peking University First Hospital, Beijing, China
| | - Nehal N Mehta
- National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - John J Voorhees
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Michael Boehnke
- Department of Biostatistics, Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA
| | - Johann E Gudjonsson
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Rajan P Nair
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Samuel K Handelman
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - James T Elder
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA; Ann Arbor Veterans Affairs Hospital, Ann Arbor, Michigan, USA
| | - Dajiang J Liu
- Department of Public Health Sciences, Pennsylvania State University College of Medicine, Pennsylvania, USA
| | - Lam C Tsoi
- Department of Dermatology, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Biostatistics, Center for Statistical Genetics, University of Michigan, Ann Arbor, MI, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor Michigan, USA.
| |
Collapse
|
6
|
Li Z, Weller SG, Drizyte-Miller K, Chen J, Krueger EW, Mehall B, Stöckli J, Casey CA, Cao H, McNiven MA. Maturation of Lipophagic Organelles in Hepatocytes Is Dependent Upon a Rab10/Dynamin-2 Complex. Hepatology 2020; 72:486-502. [PMID: 31808574 PMCID: PMC8919976 DOI: 10.1002/hep.31059] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 11/14/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND AND AIMS Hepatocytes play a central role in storage and utilization of fat by the liver. Selective breakdown of lipid droplets (LDs) by autophagy (also called lipophagy) is a key process utilized to catabolize these lipids as an energy source. How the autophagic machinery is selectively targeted to LDs, where it mediates membrane engulfment and subsequent degradation, is unclear. Recently, we have reported that two distinct GTPases, the mechanoenzyme, dynamin2 (Dyn2), and the small regulatory Rab GTPase, Rab10, work independently at distinct steps of lipophagy in hepatocytes. APPROACH AND RESULTS In an attempt to understand how these proteins are regulated and recruited to autophagic organelles, we performed a nonbiased biochemical screen for Dyn2-binding partners and found that Dyn2 actually binds Rab10 directly through a defined effector domain of Rab10 and the middle domain of Dyn2. These two GTPases can be observed to interact transiently on membrane tubules in hepatoma cells and along LD-centric autophagic membranes. Most important, we found that a targeted disruption of this interaction leads to an inability of cells to trim tubulated cytoplasmic membranes, some of which extend from lipophagic organelles, resulting in LD accumulation. CONCLUSIONS This study identifies a functional, and direct, interaction between Dyn2 and a regulatory Rab GTPase that may play an important role in hepatocellular metabolism.
Collapse
Affiliation(s)
- Zhipeng Li
- Biochemistry and Molecular Biology Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN
| | - Shaun G. Weller
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Kristina Drizyte-Miller
- Biochemistry and Molecular Biology Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN
| | - Jing Chen
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Eugene W. Krueger
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Bridget Mehall
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Jacqueline Stöckli
- Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Sydney, Australia
| | - Carol A. Casey
- Department of Internal Medicine, University of Nebraska Medical Center, 988090 Nebraska Medical Center, Omaha, NE
| | - Hong Cao
- Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN
| | - Mark A. McNiven
- Biochemistry and Molecular Biology Program, Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN,Center for Basic Research in Digestive Diseases, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN,Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN
| |
Collapse
|
7
|
Rizzelli F, Malabarba MG, Sigismund S, Mapelli M. The crosstalk between microtubules, actin and membranes shapes cell division. Open Biol 2020; 10:190314. [PMID: 32183618 PMCID: PMC7125961 DOI: 10.1098/rsob.190314] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 02/18/2020] [Indexed: 12/16/2022] Open
Abstract
Mitotic progression is orchestrated by morphological and mechanical changes promoted by the coordinated activities of the microtubule (MT) cytoskeleton, the actin cytoskeleton and the plasma membrane (PM). MTs assemble the mitotic spindle, which assists sister chromatid separation, and contact the rigid and tensile actomyosin cortex rounded-up underneath the PM. Here, we highlight the dynamic crosstalk between MTs, actin and cell membranes during mitosis, and discuss the molecular connections between them. We also summarize recent views on how MT traction forces, the actomyosin cortex and membrane trafficking contribute to spindle positioning in isolated cells in culture and in epithelial sheets. Finally, we describe the emerging role of membrane trafficking in synchronizing actomyosin tension and cell shape changes with cell-substrate adhesion, cell-cell contacts and extracellular signalling events regulating proliferation.
Collapse
Affiliation(s)
| | - Maria Grazia Malabarba
- IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy
- Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Milan, Italy
| | - Sara Sigismund
- IEO, Istituto Europeo di Oncologia IRCCS, Milan, Italy
- Dipartimento di Oncologia ed Emato-oncologia, Università degli Studi di Milano, Milan, Italy
| | | |
Collapse
|
8
|
Rópolo AS, Feliziani C, Touz MC. Unusual proteins in Giardia duodenalis and their role in survival. ADVANCES IN PARASITOLOGY 2019; 106:1-50. [PMID: 31630755 DOI: 10.1016/bs.apar.2019.07.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The capacity of the parasite Giardia duodenalis to perform complex functions with minimal amounts of proteins and organelles has attracted increasing numbers of scientists worldwide, trying to explain how this parasite adapts to internal and external changes to survive. One explanation could be that G. duodenalis evolved from a structurally complex ancestor by reductive evolution, resulting in adaptation to its parasitic lifestyle. Reductive evolution involves the loss of genes, organelles, and functions that commonly occur in many parasites, by which the host renders some structures and functions redundant. However, there is increasing data that Giardia possesses proteins able to perform more than one function. During recent decades, the concept of moonlighting was described for multitasking proteins, which involves only proteins with an extra independent function(s). In this chapter, we provide an overview of unusual proteins in Giardia that present multifunctional properties depending on the location and/or parasite requirement. We also discuss experimental evidence that may allow some giardial proteins to be classified as moonlighting proteins by examining the properties of moonlighting proteins in general. Up to date, Giardia does not seem to require the numerous redundant proteins present in other organisms to accomplish its normal functions, and thus this parasite may be an appropriate model for understanding different aspects of moonlighting proteins, which may be helpful in the design of drug targets.
Collapse
Affiliation(s)
- Andrea S Rópolo
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Constanza Feliziani
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - María C Touz
- Instituto de Investigación Médica Mercedes y Martín Ferreyra, INIMEC-CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina.
| |
Collapse
|
9
|
Tasfaout H, Cowling BS, Laporte J. Centronuclear myopathies under attack: A plethora of therapeutic targets. J Neuromuscul Dis 2019; 5:387-406. [PMID: 30103348 PMCID: PMC6218136 DOI: 10.3233/jnd-180309] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Centronuclear myopathies are a group of congenital myopathies characterized by severe muscle weakness, genetic heterogeneity, and defects in the structural organization of muscle fibers. Their names are derived from the central position of nuclei on biopsies, while they are at the fiber periphery under normal conditions. No specific therapy exists yet for these debilitating diseases. Mutations in the myotubularin phosphoinositides phosphatase, the GTPase dynamin 2, or amphiphysin 2 have been identified to cause respectively X-linked centronuclear myopathies (also called myotubular myopathy) or autosomal dominant and recessive forms. Mutations in additional genes, as RYR1, TTN, SPEG or CACNA1S, were linked to phenotypes that can overlap with centronuclear myopathies. Numerous animal models of centronuclear myopathies have been studied over the last 15 years, ranging from invertebrate to large mammalian models. Their characterization led to a partial understanding of the pathomechanisms of these diseases and allowed the recent validation of therapeutic proof-of-concepts. Here, we review the different therapeutic strategies that have been tested so far for centronuclear myopathies, some of which may be translated to patients.
Collapse
Affiliation(s)
- Hichem Tasfaout
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Belinda S. Cowling
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
- Correspondence to: Jocelyn Laporte, Tel.: 33 0 388653412; E-mail:
| |
Collapse
|
10
|
Wee P, Wang Z. Regulation of EGFR Endocytosis by CBL During Mitosis. Cells 2018; 7:cells7120257. [PMID: 30544639 PMCID: PMC6315415 DOI: 10.3390/cells7120257] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/28/2018] [Accepted: 12/04/2018] [Indexed: 12/19/2022] Open
Abstract
The overactivation of epidermal growth factor (EGF) receptor (EGFR) is implicated in various cancers. Endocytosis plays an important role in EGFR-mediated cell signaling. We previously found that EGFR endocytosis during mitosis is mediated differently from interphase. While the regulation of EGFR endocytosis in interphase is well understood, little is known regarding the regulation of EGFR endocytosis during mitosis. Here, we found that contrary to interphase cells, mitotic EGFR endocytosis is more reliant on the activation of the E3 ligase CBL. By transfecting HeLa, MCF-7, and 293T cells with CBL siRNA or dominant-negative 70z-CBL, we found that at high EGF doses, CBL is required for EGFR endocytosis in mitotic cells, but not in interphase cells. In addition, the endocytosis of mutant EGFR Y1045F-YFP (mutation at the direct CBL binding site) is strongly delayed. The endocytosis of truncated EGFR Δ1044-YFP that does not bind to CBL is completely inhibited in mitosis. Moreover, EGF induces stronger ubiquitination of mitotic EGFR than interphase EGFR, and mitotic EGFR is trafficked to lysosomes for degradation. Furthermore, we showed that, different from interphase, low doses of EGF still stimulate EGFR endocytosis by non-clathrin mediated endocytosis (NCE) in mitosis. Contrary to interphase, CBL and the CBL-binding regions of EGFR are required for mitotic EGFR endocytosis at low doses. This is due to the mitotic ubiquitination of the EGFR even at low EGF doses. We conclude that mitotic EGFR endocytosis exclusively proceeds through CBL-mediated NCE.
Collapse
Affiliation(s)
- Ping Wee
- Department of Medical Genetics and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | - Zhixiang Wang
- Department of Medical Genetics and Signal Transduction Research Group, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| |
Collapse
|
11
|
Ringer K, Riehl J, Müller M, Dewes J, Hoff F, Jacob R. The large GTPase Mx1 binds Kif5B for cargo transport along microtubules. Traffic 2018; 19:947-964. [DOI: 10.1111/tra.12616] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 09/18/2018] [Accepted: 09/18/2018] [Indexed: 01/29/2023]
Affiliation(s)
- Karina Ringer
- Department of Cell Biology and Cell Pathology; Philipps University of Marburg; Marburg Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling; Philipps University of Marburg; Marburg Germany
| | - Jana Riehl
- Department of Cell Biology and Cell Pathology; Philipps University of Marburg; Marburg Germany
| | - Manuel Müller
- Department of Cell Biology and Cell Pathology; Philipps University of Marburg; Marburg Germany
| | - Jenny Dewes
- Department of Cell Biology and Cell Pathology; Philipps University of Marburg; Marburg Germany
| | - Florian Hoff
- Department of Cell Biology and Cell Pathology; Philipps University of Marburg; Marburg Germany
| | - Ralf Jacob
- Department of Cell Biology and Cell Pathology; Philipps University of Marburg; Marburg Germany
- DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling; Philipps University of Marburg; Marburg Germany
| |
Collapse
|
12
|
Bourmoum M, Charles R, Claing A. ARF6 protects sister chromatid cohesion to ensure the formation of stable kinetochore-microtubule attachments. J Cell Sci 2018; 131:jcs216598. [PMID: 29724911 DOI: 10.1242/jcs.216598] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/25/2018] [Indexed: 01/02/2023] Open
Abstract
Sister chromatid cohesion, facilitated by the cohesin protein complex, is crucial for the establishment of stable bipolar attachments of chromosomes to the spindle microtubules and their faithful segregation. Here, we demonstrate that the GTPase ARF6 prevents the premature loss of sister chromatid cohesion. During mitosis, ARF6-depleted cells normally completed chromosome congression. However, at the metaphase plate, chromosomes failed to establish stable kinetochore-microtubule attachments because of the impaired cohesion at centromeres. As a result, the spindle assembly checkpoint (SAC) was active and cyclin B ubiquitylation and degradation were blocked. Chromosomes and/or chromatids in these cells scattered gradually from the metaphase plate to the two poles of the cell or remained blocked at the metaphase plate for hours. Our study demonstrates that the small GTP-binding protein ARF6 is essential for maintaining centromeric cohesion between sister chromatids, which is necessary for the establishment of stable k-fibres, SAC satisfaction and the onset of anaphase.
Collapse
Affiliation(s)
- Mohamed Bourmoum
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128 Succursale Centre-ville, Montreal, Quebec, Canada, H3T 1J4
| | - Ricardo Charles
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128 Succursale Centre-ville, Montreal, Quebec, Canada, H3T 1J4
| | - Audrey Claing
- Department of Pharmacology and Physiology, Faculty of Medicine, Université de Montréal, C.P. 6128 Succursale Centre-ville, Montreal, Quebec, Canada, H3T 1J4
| |
Collapse
|
13
|
Redgrove KA, Bernstein IR, Pye VJ, Mihalas BP, Sutherland JM, Nixon B, McCluskey A, Robinson PJ, Holt JE, McLaughlin EA. Dynamin 2 is essential for mammalian spermatogenesis. Sci Rep 2016; 6:35084. [PMID: 27725702 PMCID: PMC5057128 DOI: 10.1038/srep35084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 09/26/2016] [Indexed: 11/09/2022] Open
Abstract
The dynamin family of proteins play important regulatory roles in membrane remodelling and endocytosis, especially within brain and neuronal tissues. In the context of reproduction, dynamin 1 (DNM1) and dynamin 2 (DNM2) have recently been shown to act as key mediators of sperm acrosome formation and function. However, little is known about the roles that these proteins play in the developing testicular germ cells. In this study, we employed a DNM2 germ cell-specific knockout model to investigate the role of DNM2 in spermatogenesis. We demonstrate that ablation of DNM2 in early spermatogenesis results in germ cell arrest during prophase I of meiosis, subsequent loss of all post-meiotic germ cells and concomitant sterility. These effects become exacerbated with age, and ultimately result in the demise of the spermatogonial stem cells and a Sertoli cell only phenotype. We also demonstrate that DNM2 activity may be temporally regulated by phosphorylation of DNM2 via the kinase CDK1 in spermatogonia, and dephosphorylation by phosphatase PPP3CA during meiotic and post-meiotic spermatogenesis.
Collapse
Affiliation(s)
- Kate A Redgrove
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Ilana R Bernstein
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Victoria J Pye
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Bettina P Mihalas
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Jessie M Sutherland
- School of Biomedical Sciences &Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Brett Nixon
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Adam McCluskey
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Phillip J Robinson
- Cell Signalling Unit, Children's Medical Research Institute, University of Sydney, Sydney, NSW 2145, Australia
| | - Janet E Holt
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Eileen A McLaughlin
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW 2308, Australia.,PRC in Chemical Biology, University of Newcastle, Callaghan, NSW 2308, Australia.,School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand
| |
Collapse
|
14
|
Gu C, Lee HW, Garborcauskas G, Reiser J, Gupta V, Sever S. Dynamin Autonomously Regulates Podocyte Focal Adhesion Maturation. J Am Soc Nephrol 2016; 28:446-451. [PMID: 27432739 DOI: 10.1681/asn.2016010008] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 06/01/2016] [Indexed: 12/31/2022] Open
Abstract
Rho family GTPases, the prototypical members of which are Cdc42, Rac1, and RhoA, are molecular switches best known for regulating the actin cytoskeleton. In addition to the canonical small GTPases, the large GTPase dynamin has been implicated in regulating the actin cytoskeleton via direct dynamin-actin interactions. The physiologic role of dynamin in regulating the actin cytoskeleton has been linked to the maintenance of the kidney filtration barrier. Additionally, the small molecule Bis-T-23, which promotes actin-dependent dynamin oligomerization and thus, increases actin polymerization, improved renal health in diverse models of CKD, implicating dynamin as a potential therapeutic target for the treatment of CKD. Here, we show that treating cultured mouse podocytes with Bis-T-23 promoted stress fiber formation and focal adhesion maturation in a dynamin-dependent manner. Furthermore, Bis-T-23 induced the formation of focal adhesions and stress fibers in cells in which the RhoA signaling pathway was downregulated by multiple experimental approaches. Our study suggests that dynamin regulates focal adhesion maturation by a mechanism parallel to and synergistic with the RhoA signaling pathway. Identification of dynamin as one of the essential and autonomous regulators of focal adhesion maturation suggests a molecular mechanism that underlies the beneficial effect of Bis-T-23 on podocyte physiology.
Collapse
Affiliation(s)
- Changkyu Gu
- Department of Medicine, Harvard Medical School, Division of Nephrology, Massachusetts General Hospital, Charlestown, Massachusetts; and
| | - Ha Won Lee
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Garrett Garborcauskas
- Department of Medicine, Harvard Medical School, Division of Nephrology, Massachusetts General Hospital, Charlestown, Massachusetts; and
| | - Jochen Reiser
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Vineet Gupta
- Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois
| | - Sanja Sever
- Department of Medicine, Harvard Medical School, Division of Nephrology, Massachusetts General Hospital, Charlestown, Massachusetts; and
| |
Collapse
|
15
|
Two Small Molecules Block Oral Epithelial Cell Invasion by Porphyromons gingivalis. PLoS One 2016; 11:e0149618. [PMID: 26894834 PMCID: PMC4760928 DOI: 10.1371/journal.pone.0149618] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 02/03/2016] [Indexed: 11/25/2022] Open
Abstract
Porphyromonas gingivalis is a keystone pathogen of periodontitis. One of its bacterial characteristics is the ability to invade various host cells, including nonphagocytic epithelial cells and fibroblasts, which is known to facilitate P. gingivalis adaptation and survival in the gingival environment. In this study, we investigated two small compounds, Alop1 and dynasore, for their role in inhibition of P. gingivalis invasion. Using confocal microscopy, we showed that these two compounds significantly reduced invasion of P. gingivalis and its outer membrane vesicles into human oral keratinocytes in a dose-dependent manner. The inhibitory effects of dynasore, a dynamin inhibitor, on the bacterial entry is consistent with the notion that P. gingivalis invasion is mediated by a clathrin-mediated endocytic machinery. We also observed that microtubule arrangement, but not actin, was altered in the host cells treated with Alop1 or dynasore, suggesting an involvement of microtubule in this inhibitory activity. This work provides an opportunity to develop compounds against P. gingivalis infection.
Collapse
|
16
|
Peters NC, Berg CA. Dynamin-mediated endocytosis is required for tube closure, cell intercalation, and biased apical expansion during epithelial tubulogenesis in the Drosophila ovary. Dev Biol 2015; 409:39-54. [PMID: 26542010 DOI: 10.1016/j.ydbio.2015.10.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 08/09/2015] [Accepted: 10/31/2015] [Indexed: 11/28/2022]
Abstract
Most metazoans are able to grow beyond a few hundred cells and to support differentiated tissues because they elaborate multicellular, epithelial tubes that are indispensable for nutrient and gas exchange. To identify and characterize the cellular behaviors and molecular mechanisms required for the morphogenesis of epithelial tubes (i.e., tubulogenesis), we have turned to the D. melanogaster ovary. Here, epithelia surrounding the developing egg chambers first pattern, then form and extend a set of simple, paired, epithelial tubes, the dorsal appendage (DA) tubes, and they create these structures in the absence of cell division or cell death. This genetically tractable system lets us assess the relative contributions that coordinated changes in cell shape, adhesion, orientation, and migration make to basic epithelial tubulogenesis. We find that Dynamin, a conserved regulator of endocytosis and the cytoskeleton, serves a key role in DA tubulogenesis. We demonstrate that Dynamin is required for distinct aspects of DA tubulogenesis: DA-tube closure, DA-tube-cell intercalation, and biased apical-luminal cell expansion. We provide evidence that Dynamin promotes these processes by facilitating endocytosis of cell-cell and cell-matrix adhesion complexes, and we find that precise levels and sub-cellular distribution of E-Cadherin and specific Integrin subunits impact DA tubulogenesis. Thus, our studies identify novel morphogenetic roles (i.e., tube closure and biased apical expansion), and expand upon established roles (i.e., cell intercalation and adhesion remodeling), for Dynamin in tubulogenesis.
Collapse
Affiliation(s)
- Nathaniel C Peters
- University of Washington, Molecular and Cellular Biology Program and Department of Genome Sciences, Box 355065, Seattle, WA 98195-5065, United States
| | - Celeste A Berg
- University of Washington, Molecular and Cellular Biology Program and Department of Genome Sciences, Box 355065, Seattle, WA 98195-5065, United States.
| |
Collapse
|
17
|
Lee CS, Kim JM, Ghim J, Suh PG, Ryu SH. GTP-dependent interaction between phospholipase D and dynamin modulates fibronectin-induced cell spreading. Cell Signal 2015; 27:2363-70. [PMID: 26341143 DOI: 10.1016/j.cellsig.2015.08.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 08/30/2015] [Indexed: 11/27/2022]
Abstract
Phospholipase D (PLD) is one of the key enzymes to mediate a variety of cellular phenomena including endocytosis, actin rearrangement, proliferation, differentiation, and migration. Dynamin as a PLD-interacting partner is a large GTP binding protein that has been considered a mechanochemical enzyme involved in endocytosis by hydrolyzing GTP. Although both PLD and dynamin have been implicated in the regulation of actin cytoskeleton, it is not known how they have a link to regulate fibronectin (FN)-induced cell spreading. Furthermore, it is unknown whether dynamin can work as a GTP-dependent regulator through its interaction with other proteins. Here, we demonstrate that PLD can be regulated by dynamin in a GTP-dependent manner and that this is critical for FN-mediated cell spreading. First, we verified that GTP-loaded dynamin can mediate the cell spreading by FN by using dynamin's GTP binding deficient mutant (K44A). Also, we confirmed that blocking the PLD activity inhibited FN-induced cell spreading, not cell adhesion. Moreover, PLD interacted with dynamin in a GTP-dependent manner in FN signaling, and this interaction was crucial for FN-induced PLD activation and cell spreading. Also, we found that PLD mutant (R128K) that didn't have GAP activity increased the GTP-dependent interaction between PLD and dynamin; it also increased PLD activity and cell spreading. These findings suggest that the observed increase in PLD activity was through boosting the binding of PLD with dynamin and it facilitated FN-induced cell spreading. These results imply that GTP-loaded dynamin, like a small GTPase could mediate a "switch on" signaling via interaction with PLD that has a role as an effector.
Collapse
Affiliation(s)
- Chang Sup Lee
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Jong Min Kim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Jaewang Ghim
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea
| | - Pann-Ghill Suh
- School of Life Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea
| | - Sung Ho Ryu
- Department of Life Sciences, Pohang University of Science and Technology (POSTECH), Pohang 790-784, South Korea.
| |
Collapse
|
18
|
Jungbluth H, Gautel M. Pathogenic mechanisms in centronuclear myopathies. Front Aging Neurosci 2014; 6:339. [PMID: 25566070 PMCID: PMC4271577 DOI: 10.3389/fnagi.2014.00339] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 12/02/2014] [Indexed: 12/30/2022] Open
Abstract
Centronuclear myopathies (CNMs) are a genetically heterogeneous group of inherited neuromuscular disorders characterized by clinical features of a congenital myopathy and abundant central nuclei as the most prominent histopathological feature. The most common forms of congenital myopathies with central nuclei have been attributed to X-linked recessive mutations in the MTM1 gene encoding myotubularin (“X-linked myotubular myopathy”), autosomal-dominant mutations in the DNM2 gene encoding dynamin-2 and the BIN1 gene encoding amphiphysin-2 (also named bridging integrator-1, BIN1, or SH3P9), and autosomal-recessive mutations in BIN1, the RYR1 gene encoding the skeletal muscle ryanodine receptor, and the TTN gene encoding titin. Models to study and rescue the affected cellular pathways are now available in yeast, C. elegans, drosophila, zebrafish, mouse, and dog. Defects in membrane trafficking have emerged as a key pathogenic mechanisms, with aberrant T-tubule formation, abnormalities of triadic assembly, and disturbance of the excitation–contraction machinery the main downstream effects studied to date. Abnormal autophagy has recently been recognized as another important collateral of defective membrane trafficking in different genetic forms of CNM, suggesting an intriguing link to primary disorders of defective autophagy with overlapping histopathological features. The following review will provide an overview of clinical, histopathological, and genetic aspects of the CNMs in the context of the key pathogenic mechanism, outline unresolved questions, and indicate promising future lines of enquiry.
Collapse
Affiliation(s)
- Heinz Jungbluth
- Neuromuscular Service, Department of Paediatric Neurology, Evelina Children's Hospital, St Thomas' Hospital , London , UK ; Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London , London , UK ; Randall Division of Cell and Molecular Biophysics and Cardiovascular Division, King's College London BHF Centre of Research Excellence , London , UK
| | - Mathias Gautel
- Randall Division of Cell and Molecular Biophysics and Cardiovascular Division, King's College London BHF Centre of Research Excellence , London , UK
| |
Collapse
|
19
|
Intermediate Charcot-Marie-Tooth disease. Neurosci Bull 2014; 30:999-1009. [PMID: 25326399 DOI: 10.1007/s12264-014-1475-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 06/19/2014] [Indexed: 01/15/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a common neurogenetic disorder and its heterogeneity is a challenge for genetic diagnostics. The genetic diagnostic procedures for a CMT patient can be explored according to the electrophysiological criteria: very slow motor nerve conduction velocity (MNCV) (<15 m/s), slow MNCV (15-25 m/s), intermediate MNCV (25-45 m/s), and normal MNCV (>45 m/s). Based on the inheritance pattern, intermediate CMT can be divided into dominant (DI-CMT) and recessive types (RI-CMT). GJB1 is currently considered to be associated with X-linked DI-CMT, and MPZ, INF2, DNM2, YARS, GNB4, NEFL, and MFN2 are associated with autosomal DI-CMT. Moreover, GDAP1, KARS, and PLEKHG5 are associated with RI-CMT. Identification of these genes is not only important for patients and families but also provides new information about pathogenesis. It is hoped that this review will lead to a better understanding of intermediate CMT and provide a detailed diagnostic procedure for intermediate CMT.
Collapse
|
20
|
Hardy T, Lee M, Hames RS, Prosser SL, Cheary DM, Samant MD, Schultz F, Baxter JE, Rhee K, Fry AM. Multisite phosphorylation of C-Nap1 releases it from Cep135 to trigger centrosome disjunction. J Cell Sci 2014; 127:2493-506. [PMID: 24695856 PMCID: PMC4038944 DOI: 10.1242/jcs.142331] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 03/12/2014] [Indexed: 01/17/2023] Open
Abstract
During mitotic entry, centrosomes separate to establish the bipolar spindle. Delays in centrosome separation can perturb chromosome segregation and promote genetic instability. However, interphase centrosomes are physically tethered by a proteinaceous linker composed of C-Nap1 (also known as CEP250) and the filamentous protein rootletin. Linker disassembly occurs at the onset of mitosis in a process known as centrosome disjunction and is triggered by the Nek2-dependent phosphorylation of C-Nap1. However, the mechanistic consequences of C-Nap1 phosphorylation are unknown. Here, we demonstrate that Nek2 phosphorylates multiple residues within the C-terminal domain of C-Nap1 and, collectively, these phosphorylation events lead to loss of oligomerization and centrosome association. Mutations in non-phosphorylatable residues that make the domain more acidic are sufficient to release C-Nap1 from the centrosome, suggesting that it is an increase in overall negative charge that is required for this process. Importantly, phosphorylation of C-Nap1 also perturbs interaction with the core centriolar protein, Cep135, and interaction of endogenous C-Nap1 and Cep135 proteins is specifically lost in mitosis. We therefore propose that multisite phosphorylation of C-Nap1 by Nek2 perturbs both oligomerization and Cep135 interaction, and this precipitates centrosome disjunction at the onset of mitosis.
Collapse
Affiliation(s)
- Tara Hardy
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Miseon Lee
- Department of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea
| | - Rebecca S Hames
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Suzanna L Prosser
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Donna-Marie Cheary
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Mugdha D Samant
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Francisca Schultz
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Joanne E Baxter
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| | - Kunsoo Rhee
- Department of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea
| | - Andrew M Fry
- Department of Biochemistry, University of Leicester, Lancaster Road, Leicester LE1 9HN, UK
| |
Collapse
|
21
|
Wang QC, Liu J, Wang ZB, Zhang Y, Duan X, Cui XS, Kim NH, Sun SC. Dynamin 2 regulates actin-mediated spindle migration in mouse oocytes. Biol Cell 2014; 106:193-202. [DOI: 10.1111/boc.201400007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 04/09/2014] [Indexed: 02/01/2023]
Affiliation(s)
- Qiao-Chu Wang
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
| | - Jun Liu
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
| | - Zhen-Bo Wang
- State Key Laboratory of Reproductive Biology; Institute of Zoology; Chinese Academy of Sciences; Beijing 100101 China
| | - Yu Zhang
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
| | - Xing Duan
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
| | - Xiang-Shun Cui
- Department of Animal Sciences; Chungbuk National University; Cheongju Chungbuk 361-763 Korea
| | - Nam-Hyung Kim
- Department of Animal Sciences; Chungbuk National University; Cheongju Chungbuk 361-763 Korea
| | - Shao-Chen Sun
- College of Animal Science and Technology; Nanjing Agricultural University; Nanjing 210095 China
| |
Collapse
|
22
|
Menon M, Askinazi OL, Schafer DA. Dynamin2 organizes lamellipodial actin networks to orchestrate lamellar actomyosin. PLoS One 2014; 9:e94330. [PMID: 24710573 PMCID: PMC3978067 DOI: 10.1371/journal.pone.0094330] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 03/14/2014] [Indexed: 12/02/2022] Open
Abstract
Actin networks in migrating cells exist as several interdependent structures: sheet-like networks of branched actin filaments in lamellipodia; arrays of bundled actin filaments co-assembled with myosin II in lamellae; and actin filaments that engage focal adhesions. How these dynamic networks are integrated and coordinated to maintain a coherent actin cytoskeleton in migrating cells is not known. We show that the large GTPase dynamin2 is enriched in the distal lamellipod where it regulates lamellipodial actin networks as they form and flow in U2-OS cells. Within lamellipodia, dynamin2 regulated the spatiotemporal distributions of α-actinin and cortactin, two actin-binding proteins that specify actin network architecture. Dynamin2's action on lamellipodial F-actin influenced the formation and retrograde flow of lamellar actomyosin via direct and indirect interactions with actin filaments and a finely tuned GTP hydrolysis activity. Expression in dynamin2-depleted cells of a mutant dynamin2 protein that restores endocytic activity, but not activities that remodel actin filaments, demonstrated that actin filament remodeling by dynamin2 did not depend of its functions in endocytosis. Thus, dynamin2 acts within lamellipodia to organize actin filaments and regulate assembly and flow of lamellar actomyosin. We hypothesize that through its actions on lamellipodial F-actin, dynamin2 generates F-actin structures that give rise to lamellar actomyosin and for efficient coupling of F-actin at focal adhesions. In this way, dynamin2 orchestrates the global actin cytoskeleton.
Collapse
Affiliation(s)
- Manisha Menon
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Olga L. Askinazi
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Dorothy A. Schafer
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Cell Biology, University of Virginia, Charlottesville, Virginia, United States of America
| |
Collapse
|
23
|
Mark/Par-1 Marking the Polarity of Migrating Neurons. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 800:97-111. [DOI: 10.1007/978-94-007-7687-6_6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
24
|
González-Jamett AM, Haro-Acuña V, Momboisse F, Caviedes P, Bevilacqua JA, Cárdenas AM. Dynamin-2 in nervous system disorders. J Neurochem 2013; 128:210-23. [DOI: 10.1111/jnc.12455] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 09/04/2013] [Accepted: 09/12/2013] [Indexed: 12/21/2022]
Affiliation(s)
- Arlek M. González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso; Facultad de Ciencias; Universidad de Valparaíso; Valparaíso Chile
| | - Valentina Haro-Acuña
- Centro Interdisciplinario de Neurociencia de Valparaíso; Facultad de Ciencias; Universidad de Valparaíso; Valparaíso Chile
| | - Fanny Momboisse
- Centro Interdisciplinario de Neurociencia de Valparaíso; Facultad de Ciencias; Universidad de Valparaíso; Valparaíso Chile
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica; Facultad de Medicina; Universidad de Chile; Santiago Chile
| | - Jorge A. Bevilacqua
- Departamento de Neurología y Neurocirugía; Hospital Clínico Universidad de Chile; and Programa de Anatomía y Biología del Desarrollo; ICBM; Facultad de Medicina; Universidad de Chile; Santiago Chile
| | - Ana M. Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso; Facultad de Ciencias; Universidad de Valparaíso; Valparaíso Chile
| |
Collapse
|
25
|
Gibbs EM, Davidson AE, Telfer WR, Feldman EL, Dowling JJ. The myopathy-causing mutation DNM2-S619L leads to defective tubulation in vitro and in developing zebrafish. Dis Model Mech 2013; 7:157-61. [PMID: 24135484 PMCID: PMC3882057 DOI: 10.1242/dmm.012286] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
DNM2 is a ubiquitously expressed GTPase that regulates multiple subcellular processes. Mutations in DNM2 are a common cause of centronuclear myopathy, a severe disorder characterized by altered skeletal muscle structure and function. The precise mechanisms underlying disease-associated DNM2 mutations are unresolved. We examined the common DNM2-S619L mutation using both in vitro and in vivo approaches. Expression of DNM2-S619L in zebrafish led to the accumulation of aberrant vesicular structures and to defective excitation-contraction coupling. Expression of DNM2-S619L in COS7 cells resulted in defective BIN1-dependent tubule formation. These data suggest that DNM2-S619L causes disease, in part, by interfering with membrane tubulation.
Collapse
Affiliation(s)
- Elizabeth M Gibbs
- Department of Neuroscience, University of Michigan Medical Center, Ann Arbor, MI 48109-2200, USA
| | | | | | | | | |
Collapse
|
26
|
Fodrin in centrosomes: implication of a role of fodrin in the transport of gamma-tubulin complex in brain. PLoS One 2013; 8:e76613. [PMID: 24098540 PMCID: PMC3788121 DOI: 10.1371/journal.pone.0076613] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Accepted: 08/27/2013] [Indexed: 11/19/2022] Open
Abstract
Gamma-tubulin is the major protein involved in the nucleation of microtubules from centrosomes in eukaryotic cells. It is present in both cytoplasm and centrosome. However, before centrosome maturation prior to mitosis, gamma-tubulin concentration increases dramatically in the centrosome, the mechanism of which is not known. Earlier it was reported that cytoplasmic gamma-tubulin complex isolated from goat brain contains non-erythroid spectrin/fodrin. The major role of erythroid spectrin is to help in the membrane organisation and integrity. However, fodrin or non-erythroid spectrin has a distinct pattern of localisation in brain cells and evidently some special functions over its erythroid counterpart. In this study, we show that fodrin and γ-tubulin are present together in both the cytoplasm and centrosomes in all brain cells except differentiated neurons and astrocytes. Immunoprecipitation studies in purified centrosomes from brain tissue and brain cell lines confirm that fodrin and γ-tubulin interact with each other in centrosomes. Fodrin dissociates from centrosome just after the onset of mitosis, when the concentration of γ-tubulin attains a maximum at centrosomes. Further it is observed that the interaction between fodrin and γ-tubulin in the centrosome is dependent on actin as depolymerisation of microfilaments stops fodrin localization. Image analysis revealed that γ-tubulin concentration also decreased drastically in the centrosome under this condition. This indicates towards a role of fodrin as a regulatory transporter of γ-tubulin to the centrosomes for normal progression of mitosis.
Collapse
|
27
|
Sever S, Chang J, Gu C. Dynamin rings: not just for fission. Traffic 2013; 14:1194-9. [PMID: 23980695 PMCID: PMC3830594 DOI: 10.1111/tra.12116] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 08/22/2013] [Accepted: 08/26/2013] [Indexed: 12/21/2022]
Abstract
The GTPase dynamin has captivated researchers for over two decades, even managing to establish its own research field. Dynamin's allure is partly due to its unusual biochemical properties as well as its essential role in multiple cellular processes, which include the regulation of clathrin-mediated endocytosis and of actin cytoskeleton. On the basis of the classic model, dynamin oligomerization into higher order oligomers such as rings and helices directly executes the final fission reaction in endocytosis, which results in the generation of clathrin-coated vesicles. Dynamin's role in the regulation of actin cytoskeleton is mostly explained by its interactions with a number of actin-binding and -regulating proteins; however, the molecular mechanism of dynamin's action continues to elude us. Recent insights into the mechanism and role of dynamin oligomerization in the regulation of actin polymerization point to a novel role for dynamin oligomerization in the cell.
Collapse
Affiliation(s)
- Sanja Sever
- Nephrology Division, Massachusetts General Hospital, CNY 149 8.113, 149 13th Street, Charlestown, MA, 02129, USA
| | | | | |
Collapse
|
28
|
González-Jamett AM, Momboisse F, Haro-Acuña V, Bevilacqua JA, Caviedes P, Cárdenas AM. Dynamin-2 function and dysfunction along the secretory pathway. Front Endocrinol (Lausanne) 2013; 4:126. [PMID: 24065954 PMCID: PMC3776141 DOI: 10.3389/fendo.2013.00126] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/31/2013] [Indexed: 12/21/2022] Open
Abstract
Dynamin-2 is a ubiquitously expressed mechano-GTPase involved in different stages of the secretory pathway. Its most well-known function relates to the scission of nascent vesicles from the plasma membrane during endocytosis; however, it also participates in the formation of new vesicles from the Golgi network, vesicle trafficking, fusion processes and in the regulation of microtubule, and actin cytoskeleton dynamics. Over the last 8 years, more than 20 mutations in the dynamin-2 gene have been associated to two hereditary neuromuscular disorders: Charcot-Marie-Tooth neuropathy and centronuclear myopathy. Most of these mutations are grouped in the pleckstrin homology domain; however, there are no common mutations associated with both disorders, suggesting that they differently impact on dynamin-2 function in diverse tissues. In this review, we discuss the impact of these disease-related mutations on dynamin-2 function during vesicle trafficking and endocytotic processes.
Collapse
Affiliation(s)
- Arlek M. González-Jamett
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Fanny Momboisse
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Valentina Haro-Acuña
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Jorge A. Bevilacqua
- Programa de Anatomía y Biología del Desarrollo, ICBM, Facultad de Medicina, Departamento de Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Universidad de Chile, Santiago, Chile
| | - Pablo Caviedes
- Programa de Farmacología Molecular y Clínica, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ana María Cárdenas
- Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- *Correspondence: Ana María Cárdenas, Facultad de Ciencias, Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Gran Bretaña 1111, Playa Ancha 2360102, Valparaíso, Chile e-mail:
| |
Collapse
|
29
|
Strack S, Wilson TJ, Cribbs JT. Cyclin-dependent kinases regulate splice-specific targeting of dynamin-related protein 1 to microtubules. ACTA ACUST UNITED AC 2013; 201:1037-51. [PMID: 23798729 PMCID: PMC3691453 DOI: 10.1083/jcb.201210045] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The splice isoform Drp1-x01 promotes mitochondrial fission and is regulated by Cdk phosphorylation-dependent changes in microtubule association. Fission and fusion reactions determine mitochondrial morphology and function. Dynamin-related protein 1 (Drp1) is a guanosine triphosphate–hydrolyzing mechanoenzyme important for mitochondrial fission and programmed cell death. Drp1 is subject to alternative splicing of three exons with previously unknown functional significance. Here, we report that splice variants including the third but excluding the second alternative exon (x01) localized to and copurified with microtubule bundles as dynamic polymers that resemble fission complexes on mitochondria. A major isoform in immune cells, Drp1-x01 required oligomeric assembly and Arg residues in alternative exon 3 for microtubule targeting. Drp1-x01 stabilized and bundled microtubules and attenuated staurosporine-induced mitochondrial fragmentation and apoptosis. Phosphorylation of a conserved Ser residue adjacent to the microtubule-binding exon released Drp1-x01 from microtubules and promoted mitochondrial fragmentation in a splice form–specific manner. Phosphorylation by Cdk1 contributed to dissociation of Drp1-x01 from mitotic microtubules, whereas Cdk5-mediated phosphorylation modulated Drp1-x01 targeting to interphase microtubules. Thus, alternative splicing generates a latent, cytoskeletal pool of Drp1 that is selectively mobilized by cyclin-dependent kinase signaling.
Collapse
Affiliation(s)
- Stefan Strack
- Department of Pharmacology, University of Iowa, Iowa City, IA 52246, USA.
| | | | | |
Collapse
|
30
|
Abstract
Membrane trafficking and mitosis are two essential processes in eukaryotic cells. Surprisingly, many proteins best known for their role in membrane trafficking have additional 'moonlighting' functions in mitosis. Despite having proteins in common, there is insufficient evidence for a specific connection between these two processes. Instead, these phenomena demonstrate the adaptability of the membrane trafficking machinery that allows its repurposing for different cellular functions.
Collapse
Affiliation(s)
- Stephen J Royle
- Division of Biomedical Cell Biology, Warwick Medical School, Gibbet Hill Road, Coventry, CV4 7AL, UK.
| |
Collapse
|
31
|
Ikeuchi Y, de la Torre-Ubieta L, Matsuda T, Steen H, Okazawa H, Bonni A. The XLID protein PQBP1 and the GTPase Dynamin 2 define a signaling link that orchestrates ciliary morphogenesis in postmitotic neurons. Cell Rep 2013; 4:879-89. [PMID: 23994472 DOI: 10.1016/j.celrep.2013.07.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 07/17/2013] [Accepted: 07/26/2013] [Indexed: 10/26/2022] Open
Abstract
Intellectual disability (ID) is a prevalent developmental disorder of cognition that remains incurable. Here, we report that knockdown of the X-linked ID (XLID) protein polyglutamine-binding protein 1 (PQBP1) in neurons profoundly impairs the morphogenesis of the primary cilium, including in the mouse cerebral cortex in vivo. PQBP1 is localized at the base of the neuronal cilium, and targeting its WW effector domain to the cilium stimulates ciliary morphogenesis. We also find that PQBP1 interacts with Dynamin 2 and thereby inhibits its GTPase activity. Accordingly, Dynamin 2 knockdown in neurons stimulates ciliogenesis and suppresses the PQBP1 knockdown-induced ciliary phenotype. Strikingly, a mutation of the PQBP1 WW domain that causes XLID disrupts its ability to interact with and inhibit Dynamin 2 and to induce neuronal ciliogenesis. These findings define PQBP1 and Dynamin 2 as components of a signaling pathway that orchestrates neuronal ciliary morphogenesis in the brain.
Collapse
Affiliation(s)
- Yoshiho Ikeuchi
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | |
Collapse
|
32
|
Catteruccia M, Fattori F, Codemo V, Ruggiero L, Maggi L, Tasca G, Fiorillo C, Pane M, Berardinelli A, Verardo M, Bragato C, Mora M, Morandi L, Bruno C, Santoro L, Pegoraro E, Mercuri E, Bertini E, D'Amico A. Centronuclear myopathy related to dynamin 2 mutations: clinical, morphological, muscle imaging and genetic features of an Italian cohort. Neuromuscul Disord 2013; 23:229-38. [PMID: 23394783 PMCID: PMC3594745 DOI: 10.1016/j.nmd.2012.12.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 12/11/2012] [Accepted: 12/29/2012] [Indexed: 11/27/2022]
Abstract
Mutations in dynamin 2 (DNM2) gene cause autosomal dominant centronuclear myopathy and occur in around 50% of patients with centronuclear myopathy. We report clinical, morphological, muscle imaging and genetic data of 10 unrelated Italian patients with centronuclear myopathy related to DNM2 mutations. Our results confirm the clinical heterogeneity of this disease, underlining some peculiar clinical features, such as severe pulmonary impairment and jaw contracture that should be considered in the clinical follow-up of these patients. Muscle MRI showed a distinct pattern of involvement, with predominant involvement of soleus and tibialis anterior in the lower leg muscles, followed by hamstring muscles and adductor magnus at thigh level and gluteus maximus. The detection of three novel DNM2 mutations and the first case of somatic mosaicism further expand the genetic spectrum of the disease.
Collapse
Affiliation(s)
- Michela Catteruccia
- Unit for Neuromuscular and Neurodegenerative Disorders, Laboratory of Molecular Medicine, Bambino Gesù Children's Hospital, Rome, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Neuromuscular junction abnormalities in DNM2-related centronuclear myopathy. J Mol Med (Berl) 2013; 91:727-37. [DOI: 10.1007/s00109-013-0994-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 11/15/2012] [Accepted: 01/02/2013] [Indexed: 12/13/2022]
|
34
|
Menon M, Schafer DA. Dynamin: expanding its scope to the cytoskeleton. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 302:187-219. [PMID: 23351711 DOI: 10.1016/b978-0-12-407699-0.00003-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The large GTPase dynamin is well known for its actions on budded cellular membranes to generate vesicles, most often, clathrin-coated endocytic vesicles. The scope of cellular processes in which dynamin-mediated vesicle formation occurs, has expanded to include secretory vesicle formation at the Golgi, from other endosomes and nonclathrin structures, such as caveolae, as well as membrane remodeling during exocytosis and vesicle fusion. An intriguing new facet of dynamin's sphere of influence is the cytoskeleton. Cytoskeletal filament networks maintain cell shape, provide cell movement, execute cell division and orchestrate vesicle trafficking. Recent evidence supports the hypothesis that dynamin influences actin filaments and microtubules via mechanisms that are independent of its membrane-remodeling activities. This chapter discusses this emerging evidence and considers possible mechanisms of action.
Collapse
Affiliation(s)
- Manisha Menon
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | | |
Collapse
|
35
|
Radhakrishnan GK, Splitter GA. Modulation of host microtubule dynamics by pathogenic bacteria. Biomol Concepts 2012; 3:571-580. [PMID: 23585820 DOI: 10.1515/bmc-2012-0030] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The eukaryotic cytoskeleton is a vulnerable target of many microbial pathogens during the course of infection. Rearrangements of host cytoskeleton benefit microbes in various stages of their infection cycle such as invasion, motility, and persistence. Bacterial pathogens deliver a number of effector proteins into host cells for modulating the dynamics of actin and microtubule cytoskeleton. Alteration of the actin cytoskeleton is generally achieved by bacterial effectors that target the small GTPases of the host. Modulation of microtubule dynamics involves direct interaction of effector proteins with the subunits of microtubules or recruiting cellular proteins that affect microtubule dynamics. This review will discuss effector proteins from animal and human bacterial pathogens that either destabilize or stabilize host micro-tubules to advance the infectious process. A compilation of these research findings will provide an overview of known and unknown strategies used by various bacterial effectors to modulate the host microtubule dynamics. The present review will undoubtedly help direct future research to determine the mechanisms of action of many bacterial effector proteins and contribute to understanding the survival strategies of diverse adherent and invasive bacterial pathogens.
Collapse
Affiliation(s)
- Girish K Radhakrishnan
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | | |
Collapse
|
36
|
Abstract
Heterozygous mutations in dynamin 2 (DNM2) have been linked to dominant Charcot-Marie-Tooth neuropathy and centronuclear myopathy. We report the first homozygous mutation in the DNM2 protein p.Phe379Val, in three consanguineous patients with a lethal congenital syndrome associating akinesia, joint contractures, hypotonia, skeletal abnormalities, and brain and retinal hemorrhages. In vitro membrane tubulation, trafficking and GTPase assays are consistent with an impact of the DNM2p.Phe379Val mutation on endocytosis. Although DNM2 has been previously implicated in axonal and muscle maintenance, the clinical manifestation in our patients taken together with our expression analysis profile during mouse embryogenesis and knockdown approaches in zebrafish resulting in defects in muscle organization and angiogenesis support a pleiotropic role for DNM2 during fetal development in vertebrates and humans.
Collapse
|
37
|
Hehnly H, Chen CT, Powers CM, Liu HL, Doxsey S. The centrosome regulates the Rab11- dependent recycling endosome pathway at appendages of the mother centriole. Curr Biol 2012; 22:1944-50. [PMID: 22981775 DOI: 10.1016/j.cub.2012.08.022] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 07/16/2012] [Accepted: 08/13/2012] [Indexed: 12/19/2022]
Abstract
The recycling endosome localizes to a pericentrosomal region via microtubule-dependent transport. We previously showed that Sec15, an effector of the recycling endosome component, Rab11-GTPase, interacts with the mother centriole appendage protein, centriolin, suggesting an interaction between endosomes and centrosomes. Here we show that the recycling endosome associates with the appendages of the mother (older) centriole. We show that two mother centriole appendage proteins, centriolin and cenexin/ODF2, regulate association of the endosome components Rab11, the Rab11 GTP-activating protein Evi5, and the exocyst at the mother centriole. Development of an in vitro method for reconstituting endosome protein complexes onto isolated membrane-free centrosomes demonstrates that purified GTP-Rab11 but not GDP-Rab11 binds to mother centriole appendages in the absence of membranes. Moreover, centriolin depletion displaces the centrosomal Rab11 GAP, Evi5, and increases mother-centriole-associated Rab11; depletion of Evi5 also increases centrosomal Rab11. This indicates that centriolin localizes Evi5 to centriolar appendages to turn off centrosomal Rab11 activity. Finally, centriolin depletion disrupts recycling endosome organization and function, suggesting a role for mother centriole proteins in the regulation of Rab11 localization and activity at the mother centriole.
Collapse
Affiliation(s)
- Heidi Hehnly
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech 2, Suite 206, 373 Plantation Street, Worcester, MA 01605, USA
| | | | | | | | | |
Collapse
|
38
|
Haberlová J, Mazanec R, Ridzoň P, Baránková L, Nürnberg G, Nürnberg P, Sticht H, Huehne K, Seeman P, Rautenstrauss B. Phenotypic variability in a large Czech family with a dynamin 2-associated Charcot-Marie-Tooth neuropathy. J Neurogenet 2012; 25:182-8. [PMID: 22091729 DOI: 10.3109/01677063.2011.627484] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Mutations in the Dynamin 2 gene (DNM2) cause autosomal dominant centronuclear myopathy or autosomal dominant (AD) Charcot-Marie-Tooth (CMT) disease. Here the authors report one large Czech family with 15 members affected with an AD CMT phenotype of extraordinary variability. Genetic linkage analysis using SNP arrays revealed a locus of about 9.6 Mb on chromosome 19p13.1-13.2. In this critical interval, 373 genes were located. The only gene herein known to be associated with an intermediate type of CMT was Dynamin 2 (DNM2). Subsequent sequence analysis of the DNM2 gene in the index patient revealed a novel missense mutation p.Met580Thr. This missense mutation segregated with the neuropathy, indicating the causal character of this mutation. The phenotype of CMT in this family shows mild to moderate impairment with relatively preserved upper limbs and a very broad range of the onset of clinical symptoms from an early onset around the age of 12 to the late onset during the fifth decade. Electrophysiology showed an intermediate type of peripheral neuropathy. The motor median nerve conduction velocity varied from 36 m/s to normal values with signs of asymmetrical affection of peripheral nerves. No additional symptoms such as cranial nerve involvement, cataract, and signs of neutropenia or myopathy syndrome were observed in any member of the family yet. The progression was slow with no loss of ambulation. The authors suggest that the characterization of clinical variability in a single family may help to direct the genetic analysis directly to the rarely observed DNM2 mutations.
Collapse
Affiliation(s)
- J Haberlová
- Department of Child Neurology, 2nd School of Medicine, Charles University, University Hospital Motol, Prague, Czech Republic. [corrected]
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Foraker AB, Camus SM, Evans TM, Majeed SR, Chen CY, Taner SB, Corrêa IR, Doxsey SJ, Brodsky FM. Clathrin promotes centrosome integrity in early mitosis through stabilization of centrosomal ch-TOG. ACTA ACUST UNITED AC 2012; 198:591-605. [PMID: 22891263 PMCID: PMC3514040 DOI: 10.1083/jcb.201205116] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Clathrin inactivation during S phase destabilizes the microtubule-binding protein
ch-TOG, affecting its centrosomal localization and centrosome integrity during
early mitosis. Clathrin depletion by ribonucleic acid interference (RNAi) impairs mitotic
spindle stability and cytokinesis. Depletion of several clathrin-associated
proteins affects centrosome integrity, suggesting a further cell cycle function
for clathrin. In this paper, we report that RNAi depletion of CHC17 (clathrin
heavy chain 17) clathrin, but not the CHC22 clathrin isoform, induced centrosome
amplification and multipolar spindles. To stage clathrin function within the
cell cycle, a cell line expressing SNAP-tagged clathrin light chains was
generated. Acute clathrin inactivation by chemical dimerization of the SNAP-tag
during S phase caused reduction of both clathrin and ch-TOG (colonic, hepatic
tumor overexpressed gene) at metaphase centrosomes, which became fragmented.
This was phenocopied by treatment with Aurora A kinase inhibitor, suggesting a
centrosomal role for the Aurora A–dependent complex of clathrin, ch-TOG,
and TACC3 (transforming acidic coiled-coil protein 3). Clathrin inactivation in
S phase also reduced total cellular levels of ch-TOG by metaphase. Live-cell
imaging showed dynamic clathrin recruitment during centrosome maturation.
Therefore, we propose that clathrin promotes centrosome maturation by
stabilizing the microtubule-binding protein ch-TOG, defining a novel role for
the clathrin–ch-TOG–TACC3 complex.
Collapse
Affiliation(s)
- Amy B Foraker
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, CA 94143, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Mori-Yoshimura M, Okuma A, Oya Y, Fujimura-Kiyono C, Nakajima H, Matsuura K, Takemura A, Malicdan MCV, Hayashi YK, Nonaka I, Murata M, Nishino I. Clinicopathological features of centronuclear myopathy in Japanese populations harboring mutations in dynamin 2. Clin Neurol Neurosurg 2012; 114:678-83. [DOI: 10.1016/j.clineuro.2011.10.040] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 10/26/2011] [Accepted: 10/30/2011] [Indexed: 11/29/2022]
|
41
|
Böhm J, Biancalana V, Dechene ET, Bitoun M, Pierson CR, Schaefer E, Karasoy H, Dempsey MA, Klein F, Dondaine N, Kretz C, Haumesser N, Poirson C, Toussaint A, Greenleaf RS, Barger MA, Mahoney LJ, Kang PB, Zanoteli E, Vissing J, Witting N, Echaniz-Laguna A, Wallgren-Pettersson C, Dowling J, Merlini L, Oldfors A, Bomme Ousager L, Melki J, Krause A, Jern C, Oliveira ASB, Petit F, Jacquette A, Chaussenot A, Mowat D, Leheup B, Cristofano M, Poza Aldea JJ, Michel F, Furby A, Llona JEB, Van Coster R, Bertini E, Urtizberea JA, Drouin-Garraud V, Béroud C, Prudhon B, Bedford M, Mathews K, Erby LAH, Smith SA, Roggenbuck J, Crowe CA, Brennan Spitale A, Johal SC, Amato AA, Demmer LA, Jonas J, Darras BT, Bird TD, Laurino M, Welt SI, Trotter C, Guicheney P, Das S, Mandel JL, Beggs AH, Laporte J. Mutation spectrum in the large GTPase dynamin 2, and genotype-phenotype correlation in autosomal dominant centronuclear myopathy. Hum Mutat 2012; 33:949-59. [PMID: 22396310 DOI: 10.1002/humu.22067] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2011] [Accepted: 02/20/2012] [Indexed: 11/11/2022]
Abstract
Centronuclear myopathy (CNM) is a genetically heterogeneous disorder associated with general skeletal muscle weakness, type I fiber predominance and atrophy, and abnormally centralized nuclei. Autosomal dominant CNM is due to mutations in the large GTPase dynamin 2 (DNM2), a mechanochemical enzyme regulating cytoskeleton and membrane trafficking in cells. To date, 40 families with CNM-related DNM2 mutations have been described, and here we report 60 additional families encompassing a broad genotypic and phenotypic spectrum. In total, 18 different mutations are reported in 100 families and our cohort harbors nine known and four new mutations, including the first splice-site mutation. Genotype-phenotype correlation hypotheses are drawn from the published and new data, and allow an efficient screening strategy for molecular diagnosis. In addition to CNM, dissimilar DNM2 mutations are associated with Charcot-Marie-Tooth (CMT) peripheral neuropathy (CMTD1B and CMT2M), suggesting a tissue-specific impact of the mutations. In this study, we discuss the possible clinical overlap of CNM and CMT, and the biological significance of the respective mutations based on the known functions of dynamin 2 and its protein structure. Defects in membrane trafficking due to DNM2 mutations potentially represent a common pathological mechanism in CNM and CMT.
Collapse
Affiliation(s)
- Johann Böhm
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, INSERM U964/CNRS UMR7104, University of Strasbourg, Collège de France, Illkirch, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Sigismund S, Confalonieri S, Ciliberto A, Polo S, Scita G, Di Fiore PP. Endocytosis and signaling: cell logistics shape the eukaryotic cell plan. Physiol Rev 2012; 92:273-366. [PMID: 22298658 DOI: 10.1152/physrev.00005.2011] [Citation(s) in RCA: 236] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Our understanding of endocytosis has evolved remarkably in little more than a decade. This is the result not only of advances in our knowledge of its molecular and biological workings, but also of a true paradigm shift in our understanding of what really constitutes endocytosis and of its role in homeostasis. Although endocytosis was initially discovered and studied as a relatively simple process to transport molecules across the plasma membrane, it was subsequently found to be inextricably linked with almost all aspects of cellular signaling. This led to the notion that endocytosis is actually the master organizer of cellular signaling, providing the cell with understandable messages that have been resolved in space and time. In essence, endocytosis provides the communications and supply routes (the logistics) of the cell. Although this may seem revolutionary, it is still likely to be only a small part of the entire story. A wealth of new evidence is uncovering the surprisingly pervasive nature of endocytosis in essentially all aspects of cellular regulation. In addition, many newly discovered functions of endocytic proteins are not immediately interpretable within the classical view of endocytosis. A possible framework, to rationalize all this new knowledge, requires us to "upgrade" our vision of endocytosis. By combining the analysis of biochemical, biological, and evolutionary evidence, we propose herein that endocytosis constitutes one of the major enabling conditions that in the history of life permitted the development of a higher level of organization, leading to the actuation of the eukaryotic cell plan.
Collapse
Affiliation(s)
- Sara Sigismund
- IFOM, Fondazione Istituto FIRC di Oncologia Molecolare, Milan, Italy
| | | | | | | | | | | |
Collapse
|
43
|
Bucci C, Bakke O, Progida C. Charcot-Marie-Tooth disease and intracellular traffic. Prog Neurobiol 2012; 99:191-225. [PMID: 22465036 PMCID: PMC3514635 DOI: 10.1016/j.pneurobio.2012.03.003] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 12/23/2011] [Accepted: 03/13/2012] [Indexed: 12/23/2022]
Abstract
Mutations of genes whose primary function is the regulation of membrane traffic are increasingly being identified as the underlying causes of various important human disorders. Intriguingly, mutations in ubiquitously expressed membrane traffic genes often lead to cell type- or organ-specific disorders. This is particularly true for neuronal diseases, identifying the nervous system as the most sensitive tissue to alterations of membrane traffic. Charcot-Marie-Tooth (CMT) disease is one of the most common inherited peripheral neuropathies. It is also known as hereditary motor and sensory neuropathy (HMSN), which comprises a group of disorders specifically affecting peripheral nerves. This peripheral neuropathy, highly heterogeneous both clinically and genetically, is characterized by a slowly progressive degeneration of the muscle of the foot, lower leg, hand and forearm, accompanied by sensory loss in the toes, fingers and limbs. More than 30 genes have been identified as targets of mutations that cause CMT neuropathy. A number of these genes encode proteins directly or indirectly involved in the regulation of intracellular traffic. Indeed, the list of genes linked to CMT disease includes genes important for vesicle formation, phosphoinositide metabolism, lysosomal degradation, mitochondrial fission and fusion, and also genes encoding endosomal and cytoskeletal proteins. This review focuses on the link between intracellular transport and CMT disease, highlighting the molecular mechanisms that underlie the different forms of this peripheral neuropathy and discussing the pathophysiological impact of membrane transport genetic defects as well as possible future ways to counteract these defects.
Collapse
Affiliation(s)
- Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), University of Salento, Via Provinciale Monteroni, 73100 Lecce, Italy.
| | | | | |
Collapse
|
44
|
Brodie KM, Henderson BR. Characterization of BRCA1 protein targeting, dynamics, and function at the centrosome: a role for the nuclear export signal, CRM1, and Aurora A kinase. J Biol Chem 2012; 287:7701-16. [PMID: 22262852 PMCID: PMC3293534 DOI: 10.1074/jbc.m111.327296] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/16/2012] [Indexed: 02/04/2023] Open
Abstract
BRCA1 is a DNA damage response protein and functions in the nucleus to stimulate DNA repair and at the centrosome to inhibit centrosome overduplication in response to DNA damage. The loss or mutation of BRCA1 causes centrosome amplification and abnormal mitotic spindle assembly in breast cancer cells. The BRCA1-BARD1 heterodimer binds and ubiquitinates γ-tubulin to inhibit centrosome amplification and promote microtubule nucleation; however regulation of BRCA1 targeting and function at the centrosome is poorly understood. Here we show that both N and C termini of BRCA1 are required for its centrosomal localization and that BRCA1 moves to the centrosome independently of BARD1 and γ-tubulin. Mutations in the C-terminal phosphoprotein-binding BRCT domain of BRCA1 prevented localization to centrosomes. Photobleaching experiments identified dynamic (60%) and immobilized (40%) pools of ectopic BRCA1 at the centrosome, and these are regulated by the nuclear export receptor CRM1 (chromosome region maintenance 1) and BARD1. CRM1 mediates nuclear export of BRCA1, and mutation of the export sequence blocked BRCA1 regulation of centrosome amplification in irradiated cells. CRM1 binds to undimerized BRCA1 and is displaced by BARD1. Photobleaching assays implicate CRM1 in driving undimerized BRCA1 to the centrosome and revealed that when BRCA1 subsequently binds to BARD1, it is less well retained at centrosomes, suggesting a mechanism to accelerate BRCA1 release after formation of the active heterodimer. Moreover, Aurora A binding and phosphorylation of BRCA1 enhanced its centrosomal retention and regulation of centrosome amplification. Thus, CRM1, BARD1 and Aurora A promote the targeting and function of BRCA1 at centrosomes.
Collapse
Affiliation(s)
- Kirsty M. Brodie
- From the Westmead Institute for Cancer Research, University of Sydney, Westmead Millennium Institute at Westmead Hospital, Darcy Road (P.O. Box 412), Westmead, New South Wales 2145, Australia
| | - Beric R. Henderson
- From the Westmead Institute for Cancer Research, University of Sydney, Westmead Millennium Institute at Westmead Hospital, Darcy Road (P.O. Box 412), Westmead, New South Wales 2145, Australia
| |
Collapse
|
45
|
Brodie KM, Mok MTS, Henderson BR. Characterization of BARD1 targeting and dynamics at the centrosome: the role of CRM1, BRCA1 and the Q564H mutation. Cell Signal 2012; 24:451-459. [PMID: 21982881 DOI: 10.1016/j.cellsig.2011.09.024] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 09/23/2011] [Accepted: 09/24/2011] [Indexed: 01/25/2023]
Abstract
BARD1 heterodimerizes with BRCA1, forming an E3 ubiquitin ligase that functions at nuclear foci to repair DNA damage and the centrosome to regulate mitosis. We compared BARD1 recruitment at these structures using fluorescence recovery after photobleaching assays to measure YFP-BARD1 dynamics in live cells. In nuclei at ionizing radiation-induced foci, 20% of the BARD1 pool was immobile and 80% of slow mobility exhibiting a recovery time >500 s. In contrast, at centrosomes 83% of BARD1 was rapidly mobile with extremely fast turnover (recovery time ~20s). The ~25-fold faster exchange of BARD1 at centrosomes correlated with BRCA1-independent recruitment. We mapped key targeting sequences to a combination of the N and C-termini, and showed that mutation of the nuclear export signal reduced centrosome localization by 50%, revealing a role for CRM1. Deletion of the sequence 128-550 increased BARD1 turnover at the centrosome, consistent with a role in transient associations. Conversely, the cancer mutation Q564H reduced turnover by 25%. BARD1 is one of the most highly mobile proteins yet detected at the centrosome, and in contrast to its localization at DNA repair foci, which requires dimerization with BRCA1, targeting of BARD1 to the centrosome occurs prior to heterodimerization and its rapid turnover may provide a mechanism to regulate dimer formation.
Collapse
Affiliation(s)
- Kirsty M Brodie
- Westmead Institute for Cancer Research, The University of Sydney, Westmead Millennium Institute at Westmead Hospital, Westmead, NSW 2145, Australia
| | - Myth T S Mok
- Westmead Institute for Cancer Research, The University of Sydney, Westmead Millennium Institute at Westmead Hospital, Westmead, NSW 2145, Australia
| | - Beric R Henderson
- Westmead Institute for Cancer Research, The University of Sydney, Westmead Millennium Institute at Westmead Hospital, Westmead, NSW 2145, Australia.
| |
Collapse
|
46
|
Grigera PR, Ma L, Borgman CA, Pinto AF, Sherman NE, Parsons JT, Fox JW. Mass spectrometric analysis identifies a cortactin-RCC2/TD60 interaction in mitotic cells. J Proteomics 2012; 75:2153-9. [PMID: 22282019 DOI: 10.1016/j.jprot.2012.01.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2011] [Revised: 01/08/2012] [Accepted: 01/09/2012] [Indexed: 10/24/2022]
Abstract
Cortactin is an F-actin binding protein that functions as a scaffold to regulate Arp2/3 mediated actin polymerization in lamellipodia and invadopodia formation as well as functioning in cell migration and endocytosis of many different cell types. In light of the fact that regulated actin polymerization is critical for many cellular processes we launched a search for novel cortactin interactions with cellular proteins that might indicate heretofore undescribed biological activities supported by cortactin. Using a modified stable isotope labeling in cell culture (SILAC) approach in HEK293 cells and Flag-tagged cortactin (F-cortactin) as bait, we identified a limited set of cortactin interactions including several proteins which have not previously been identified as cortactin associated proteins. Among these were serine/threonine-protein phosphatase 2A subunit beta (PP2A-beta) and RCC2/TD60, a Rac guanine nucleotide exchange factor (GEF) required for completion of mitosis and cytokinesis. The interaction between cortactin and RCC2/TD60 was verified in cell lysates immunoprecitated with anti-RCC2/TD60 antibody. Furthermore, cortactin was localized by immunofluorescence in the equatorial plane of dividing HeLa cells in the region where RCC2/TD60 has previously been localized thus providing support for a complex containing cortactin and RCC2/TD60 complex that may play a functional role in cells undergoing mitosis.
Collapse
Affiliation(s)
- Pablo R Grigera
- Department of Microbiology, Immunology and Cancer Biology, University of Virginia Health System, Charlottesville, VA 22908, United States
| | | | | | | | | | | | | |
Collapse
|
47
|
Koutsopoulos OS, Koch C, Tosch V, Böhm J, North KN, Laporte J. Mild functional differences of dynamin 2 mutations associated to centronuclear myopathy and Charcot-Marie Tooth peripheral neuropathy. PLoS One 2011; 6:e27498. [PMID: 22096584 PMCID: PMC3214065 DOI: 10.1371/journal.pone.0027498] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 10/18/2011] [Indexed: 11/18/2022] Open
Abstract
The large GTPase dynamin 2 is a key player in membrane and cytoskeletal dynamics mutated in centronuclear myopathy (CNM) and Charcot-Marie Tooth (CMT) neuropathy, two discrete dominant neuromuscular disorders affecting skeletal muscle and peripheral nerves respectively. The molecular basis for the tissue-specific phenotypes observed and the physiopathological mechanisms linked to dynamin 2 mutations are not well established. In this study, we have analyzed the impact of CNM and CMT implicated dynamin 2 mutants using ectopic expression of four CNM and two CMT mutations, and patient fibroblasts harboring two dynamin 2 CNM mutations in established cellular processes of dynamin 2 action. Wild type and CMT mutants were seen in association with microtubules whereas CNM mutants lacked microtubules association and did not disrupt interphase microtubules dynamics. Most dynamin 2 mutants partially decreased clathrin-mediated endocytosis when ectopically expressed in cultured cells; however, experiments in patient fibroblasts suggested that endocytosis is overall not defective. Furthermore, CNM mutants were seen in association with enlarged clathrin stained structures whereas the CMT mutant constructs were associated with clathrin structures that appeared clustered, similar to the structures observed in Dnm1 and Dnm2 double knock-out cells. Other roles of dynamin 2 including its interaction with BIN1 (amphiphysin 2), and its function in Golgi maintenance and centrosome cohesion were not significantly altered. Taken together, these mild functional defects are suggestive of differences between CMT and CNM disease-causing dynamin 2 mutants and suggest that a slight impairment in clathrin-mediated pathways may accumulate over time to foster the respective human diseases.
Collapse
Affiliation(s)
- Olga S. Koutsopoulos
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Catherine Koch
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Valerie Tosch
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Johann Böhm
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Kathryn N. North
- Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, Sydney, Australia
- Discipline of Paediatrics and Child Health, Faculty of Medicine, University of Sydney, Australia
| | - Jocelyn Laporte
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
- * E-mail:
| |
Collapse
|
48
|
Chircop M, Sarcevic B, Larsen MR, Malladi CS, Chau N, Zavortink M, Smith CM, Quan A, Anggono V, Hains PG, Graham ME, Robinson PJ. Phosphorylation of dynamin II at serine-764 is associated with cytokinesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1813:1689-99. [DOI: 10.1016/j.bbamcr.2010.12.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 11/30/2010] [Accepted: 12/21/2010] [Indexed: 10/18/2022]
|
49
|
Scharadin TM, Jiang H, Jans R, Rorke EA, Eckert RL. TIG3 tumor suppressor-dependent organelle redistribution and apoptosis in skin cancer cells. PLoS One 2011; 6:e23230. [PMID: 21858038 PMCID: PMC3157364 DOI: 10.1371/journal.pone.0023230] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 07/12/2011] [Indexed: 12/31/2022] Open
Abstract
TIG3 is a tumor suppressor protein that limits keratinocyte survival during normal differentiation. It is also important in cancer, as TIG3 level is reduced in tumors and in skin cancer cell lines, suggesting that loss of expression may be required for cancer cell survival. An important goal is identifying how TIG3 limits cell survival. In the present study we show that TIG3 expression in epidermal squamous cell carcinoma SCC-13 cells reduces cell proliferation and promotes morphological and biochemical apoptosis. To identify the mechanism that drives these changes, we demonstrate that TIG3 localizes near the centrosome and that pericentrosomal accumulation of TIG3 alters microtubule and microfilament organization and organelle distribution. Organelle accumulation at the centrosome is a hallmark of apoptosis and we demonstrate that TIG3 promotes pericentrosomal organelle accumulation. These changes are associated with reduced cyclin D1, cyclin E and cyclin A, and increased p21 level. In addition, Bax level is increased and Bcl-XL level is reduced, and cleavage of procaspase 3, procaspase 9 and PARP is enhanced. We propose that pericentrosomal localization of TIG3 is a key event that results in microtubule and microfilament redistribution and pericentrosomal organelle clustering and that leads to cancer cell apoptosis.
Collapse
Affiliation(s)
- Tiffany M. Scharadin
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Haibing Jiang
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Ralph Jans
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Ellen A. Rorke
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
| | - Richard L. Eckert
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Dermatology, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- Department of Obstetrics and Gynecology and Reproductive Sciences, School of Medicine, University of Maryland, Baltimore, Maryland, United States of America
- * E-mail:
| |
Collapse
|
50
|
Lauwaet T, Smith AJ, Reiner DS, Romijn EP, Wong CCL, Davids BJ, Shah SA, Yates JR, Gillin FD. Mining the Giardia genome and proteome for conserved and unique basal body proteins. Int J Parasitol 2011; 41:1079-92. [PMID: 21723868 DOI: 10.1016/j.ijpara.2011.06.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/25/2011] [Accepted: 06/01/2011] [Indexed: 12/27/2022]
Abstract
Giardia lamblia is a flagellated protozoan parasite and a major cause of diarrhoea in humans. Its microtubular cytoskeleton mediates trophozoite motility, attachment and cytokinesis, and is characterised by an attachment disk and eight flagella that are each nucleated in a basal body. To date, only 10 giardial basal body proteins have been identified, including universal signalling proteins that are important for regulating mitosis or differentiation. In this study, we have exploited bioinformatics and proteomic approaches to identify new Giardia basal body proteins and confocal microscopy to confirm their localisation in interphase trophozoites. This approach identified 75 homologs of conserved basal body proteins in the genome including 65 not previously known to be associated with Giardia basal bodies. Thirteen proteins were confirmed to co-localise with centrin to the Giardia basal bodies. We also demonstrate that most basal body proteins localise to additional cytoskeletal structures in interphase trophozoites. This might help to explain the roles of the four pairs of flagella and Giardia-specific organelles in motility and differentiation. A deeper understanding of the composition of the Giardia basal bodies will contribute insights into the complex signalling pathways that regulate its unique cytoskeleton and the biological divergence of these conserved organelles.
Collapse
Affiliation(s)
- Tineke Lauwaet
- Department of Pathology, University of California San Diego, San Diego, CA 92103, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|